UC-Riverside PEMS Workshop March 24, In-Use Testing Experiences Joel Squire, Caterpillar, Inc.

Transcription

1 UC-Riverside PEMS Workshop March 24, 2011 In-Use Testing Experiences Joel Squire, Caterpillar, Inc.

2 Agenda Overview of Caterpillar s in-use testing programs Performance Comparison of PEMS PEMS Data Reduction Programs Specific experiences with AVL PM-PEMS Non-road in-use testing Challenges

3 Caterpillar s IUT Program at a Glance PEMS Applications - On-Highway In-Use Testing - Non-Road Applications - Marine Field Testing PEMS Instruments - Sensors Inc. SEMTECH-DS - Horiba OBS, and TRPM - AVL 494 (483 Microsoot Sensor and Gravimetric Filter Box) Comparisons shown using blind approach

4 Percent of Total Tests 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% PEMS Success Rate = Successful test attempts / Total test attempts 85% 79% 44% 27% PEMS A PEMS B PEMS C PEMS D Gaseous PEMS PM PEMS Results do not reflect out of the box failures (Only failures that required a complete retest) Still not comfortable with PEMS reliability Further development is required

5 PEMS Data Processing Data reduction programs are a key element for regulatory compliance programs EPA report generation is a requirement, but complex Would like to see this simplified (upcoming Non-Road rule, improvements to Truck, etc.) Caterpillar has experience with three different PEMS data reduction programs Sensors Horiba AVL Significant differences between data-processors Required EPA Report Creation abilities are poor or lacking NTE Event determination can be different between processors Basic vs. Advanced plotting features Importing foreign data files Would prefer a built in engineering units conversion utility Calculation errors and software bugs continue to plague all processors. Ability to use multiple calculation schemes Mass calculations (EPA Method 2 and 3) US NTE/European WBW schemes

6 AVL 494 PEMS Experience AVL PM-PEMS Overview AVL 483 Microsoot sensor (Real-time measurement) Gravimetric Filter (constant dilution partial flow) Applies Total PM correction to the AVL 483 signal for real-time resolution of PM Pros Setup and operation is relatively less complicated than other options Enclosures are rugged (dust/drip proof), Ideal for Non-Road Machinery Heated Sample line is very flexible and durable Can be operated independently from gaseous PEMS Only available PM PEMS that can use EPA Method 3 (ECM Fuel Rate) Can upgrade existing AVL 483 to a PM-PEMS Cons Filter pucks are very small and hard to handle (leads to filter mishandling) Some dust still gets into the unit (Non-Road Applications) Heated Sample line needs to be longer (Cat Only has a 2 meter line) Needs a separate host computer to log a data file Has problems operating in somewhat extreme temperatures (hot/cold)

7 AVL 494 PEMS Experience Concerto Processor Data Processing Concerto can process both Gaseous and PM Data Imports data from other Gaseous PEMS Developed for the on-highway in-use test reporting Non-Road in-use testing templates need to be added US Non-road In-use rule will require new template (dev. time) Can also perform work-based-window calculations Required for European in-service conformity

8 Periodic Calibrations and Checks Procedure Interval Comments CFO Calibration (Filter Flow, MSS Flow) 365 Days NIST Traceable Manufacturer Cal. Calibration of Dilution MFC Pre-Test "Mirrored" to internal CFO's Sample Flow Check 35 Days Within +/- 3% accuracy at each dilution ratio Filter Temperature Linearity Check 35 Days Meets Linearity Criteria Vacuum Leak Check Pre-Test Protocol built into the AVL PEMS Absorber Window Calibration for Micro Soot Sensor Pre-Test Within +/- 1% accuracy We are looking for a solution to perform the CFO calibration in-house as opposed to sending out. Currently unable to perform the filter temperature linearity due to equipment constraints. May be useful to have ability to perform background check before sending the unit into the field.

9 Tempeerature (Deg F) Non-Road In-Use Testing Challenges Ambient Conditions PEMS will have increased exposure to ambient conditions, more so than on-highway (No ram air or air-conditioned cab) Vibration, dust will drive additional maintenance and failure costs to PEMS Ambient Temps can be drastically different on machine Temperature deltas on a Non-road Application Actual Ambient Temp 114 PEMS Measured Temp PEMS temperature is measured near air intake via weather probe Actual ambient temperature is acquired from local weather station Even with PEMS modifications, PEMS still failed

10 High Ambient Temps on Excavator on a 78 Deg F Day. Flow meter and sample line Gaseous PEMS Excavator was used to simulate truck loading and trenching applications PEMS mounted on top of cab An environmental case was used to protect the PEMS from water and dust. End covers of the environmental case still had to be removed, exposing the PEMS, to keep the Chiller from overheating. PM PEMS was more sensitive to the heat and was removed from the machine. Dilution control failed. PEMS originally placed here Gasoline Generator

11 Expected Non-Road In-Use Testing Challenges Agricultural Applications Strict harvest Schedule Lack of use during non-harvest seasons Customer Compensation for Large Machinery Monetary loss for machine taken out of service is significant, potentially tens of thousands of dollars per day.

12 Summary PEMS Maintenance/Failures continue to be costly $13,097/unit for repairs & calibrations in 2010 alone Significant time spent re-testing engines We should not have to bring 2 PEMS on each test assignment The cost of performing in-use testing is still quite high. Data Processors are an important part of the PEMS package But not without their problems either Especially in terms of EPA report generation Non-Road in-use testing will be very challenging More so than on-highway in terms of recruiting and testing engines We would like to ask regulatory agencies to simplify the reporting requirements as more experience is gained